-threatening situation. >> when there are medical problems in the sky, 90% of commercial airlines in the u.s. will call medaire. >> typically the captain or flight attendant will contact us through satellite phone or even through the aircraft radio. >> the private company based in tempe, arizona, gives advice to pilots, flight attendants, or any medical professional who may be on board. >> medical events are actually rare. we can't estimate one medical event for every 30,000 passengers carried. >> how often do in-flight medical events occur? >> that's a very good question. nobody really knows. >> the faa does not require airlines to report in-flight medical events. >> they're in a contained environment, so knowing what the most common illnesses and injuries and events that occur can really help better prepare with them in a more effective manner. >> the faa does require that airlines carry certain items in a medical kit. we discovered what's in those kits can vary from airline to airline. for more information, go to our website, nbcbayarea.com, and be sure to watch our full information at 11:00. >> oka